China appears to be laying the groundwork for the mass collection of DNA samples from residents of a restive, largely Muslim region that’s been under a security crackdown, rights observers and independent experts said Tuesday.

Police in western China’s Xinjiang region confirmed to The Associated Press that they are in the process of purchasing at least $8.7 million in equipment to analyse DNA samples.

Observers from Human Rights Watch said they’ve seen evidence of almost $3 million in additional purchases related to DNA testing. They warned such a collection programme could be used as a way for authorities to beef up their political control.

The move comes after Chinese authorities last year reportedly required Xinjiang residents to submit DNA samples, fingerprints and voice records to obtain passports or travel abroad.

In one of the most recent attacks, eight people, including three assailants, were killed in a February knife attack in southern Xinjiang’s Pishan County, which borders Pakistan.

Chinese authorities seeking to counter religious extremism among the Uighurs have taken increasingly aggressive steps to quell the unrest. Those have included mandatory satellite tracking systems for vehicles in some areas, rewards for terror-related tips and prohibitions against women wearing veils and men growing beards.

The purchases of DNA testing equipment in Xinjiang were confirmed by an official at the regional Public Security Bureau. The official, who gave only her surname, Huang, said a supplier already had been found. In Xinjiang’s Sheche County, suppliers were being sought for voiceprint collection systems and 3-D portrait systems, according to a security official surnamed Yin, who declined to give further details.

If used at full capacity, the new equipment could be used to profile up to 10,000 DNA samples a day and several million a year, said Yves Moreau, a computational biologist specialising in genome analysis and DNA privacy at the University of Leuven in Belgium.

The scale of the purchases raises “a legitimate concern that Chinese authorities could be planning to DNA profile a large fraction, or even all” of the Uighur people in Xinjiang, Moreau said.

Since it started collecting DNA profiles in 1989, China has amassed the unique genetic information on more than 40 million people, constituting the world’s largest DNA database, according to a study last year by forensic researchers at the China Ministry of Public Security.

Unlike many other countries, China lacks legal protections to guard people’s privacy and prevent their genetic information from being misused, said Helen Wallace, founder of the British group GeneWatch.

“Xinjiang is already an oppressive region with a high level of surveillance,” said Human Rights Watch researcher Maya Wang. “To collect even more information on a mass scale unrelated to criminal investigation opens the door for an even greater level of surveillance and control.”

Government-sponsored DNA databases compile the genetic markers present in each individual, typically from blood, saliva or hair samples. They’re used by law enforcement agencies around the globe as evidence in criminal prosecutions and to monitor prior offenders.

In the United States, where laws generally limit DNA collection to people who have been arrested, the Federal Bureau of Investigation has 12.8 million offenders in its DNA database, according to the agency. That’s almost 4 percent of the total US population. The United Kingdom has 5.2 million people in its database, or about 8 percent of its population, according the British government.

China’s database now covers about 3 percent of its population. It’s been used by authorities to reunite abducted children with their parents. It was also used in a highly publicised case last year to help track down a serial killer who authorities said admitted to the murders of 11 women and girls over a 14-year period.

“It’s clear there’s a fairly large infrastructure being built for DNA collection and they’re planning to expand that further,” Wallace said. “I would like to see China put their legal database on clear legal footing. That includes the kinds of safeguards we see in other countries.”

Chinese President Xi Jinping on Monday praised the normalisation of relations with Norway, six years after a dispute over the Nobel Peace Prize, as Norway’s prime minister said she was glad to be back.

The visit by Erna Solberg is the first high-level exchange since December, when the two countries normalised ties that soured after the Oslo-based Nobel Committee awarded the 2010 Peace Prize to the still-imprisoned Chinese activist Liu Xiaobo.

Solberg’s visit, the first to China by a Norwegian prime minister for a decade, began Friday and will end Tuesday.

“Your visit this time holds a lot of significance,” Xi told her at a meeting in the Great Hall of the People.

He noted that Norway had been one of the first Western countries to recognise the People’s Republic of China, and one of the earliest to recognise its status as a market economy.

Solberg said she was “delighted to be back” in China and Norway’s king was also happy to accept Xi’s invitation to visit in the autumn of 2018.

On Friday she met Premier Li Keqiang, signing numerous cooperation documents including an agreement to resume negotiations on a free trade pact.

Liu Xiaobo was sentenced in 2009 to 11 years in jail for “subversion”, after he co-wrote a text calling for democracy in China. His wife Liu Xia remains under house arrest.

Diplomatic relations and trade talks were frozen after Liu was given his Nobel. Norway’s salmon industry suffered as exports to China were halted.

Exchanges only resumed last December after Norway pledged its commitment to the one-China policy and respect for China’s territorial integrity.

The Western media often blamed China for “converting its economic power into strategic influence”, but cooperating on economic goals was ultimately more beneficial than clashing over human rights issues, an editorial in the Global Times newspaper, which often takes a nationalistic tone, said Monday.

An opposition lawmaker filed an impeachment complaint in the Philippine Congress on Thursday against President Rodrigo Duterte, calling for his removal for what he said were high crimes, betrayal of public trust and abuse of power.

Lower house representative Gary Alejano accused Duterte of a laundry list of offences he said were worthy of impeachment, from concealing assets and conflicts of interest to drugs-related extrajudicial killings and running an alleged “death squad” when he was Davao City mayor.

Duterte has rejected similar allegations levelled at him in the past. His spokesman on Thursday said Alejano was trying to create doubts among the public about the administration. Alejano said his aim was to give Filipinos a chance to speak up against a powerful president.

“Our goal with this complaint is to be a vehicle for Filipinos to have a voice to oppose and fight against the abuses and crimes of President Duterte,” Alejano told a televised news conference.

“We know it’s an uphill battle … but we believe that many will support this complaint.”He said Duterte’s actions were a “culpable violation of the constitution, engaging in bribery, betrayal of public trust, graft and corruption and other high crimes”.

Alejano accused Duterte of having a state policy of killing drug offenders. Presidential spokesman Ernesto Abella said the complaint was part of a wider plot by opponents to undermine the Duterte administration.

“It seems rather dramatic that everything seems to be so coordinated at this stage,” Abella told reporters. “It looks like they’re scraping the bottom of the barrel.”